Fire inhibitor and extinguisher



Feb. 6, 1962 D. POWELL 3,019,843

FIRE INHIBITOR AND EXTINGUISHER Filed July 27, 1956 2 Sheets-Sheet 1 INVEN TOR. 54 W50 Pan 6 Feb. 6, 1962 Filed July 27, 1956 FIRE 2Sheets-Sheet 2 INVENTOR. Dawson Powell BYZMMQQ/M z r teed The presentinvention relates generally to fire prevention and extinguishment, andhas particular reference to fire control in connection with tank storageof flammable liquids and compressed flammable gases which are stored asliquids.

A primary object of my invention is the provision of means forpreventing and/or extinguishing fires, such as are likely to be fed byvapors escaping from storage tanks for volatile petroleum liquids, oils,and LPG liquefied petroleum gas) maintained in the liquid state byconditions of pressure and temperature.

Another object of the instant invention is the provision of means of theabove described character which will be equally as effective with bothhorizontaland vertical-type storage tanks, and which, in connection withthe latter, may be utilized whether the tank has a closed or open top.

Another object of my invention is the provision of fire prevention andextinguishing means which may effectively be used wherever flammableliquids or gases are stored, some illustrative applications beFnghouseholdsize LPG storage tanks, small and large industrial-size LPGstorage tanks, including so-called portable tanks, railroad LPG tankcars and other flammable liquid railroad tank cars, truck delivery tanksfor animal, vegetable and mineral oils and LPG, oil-filled transformers,quench and dip tanks, and fuel tanks in airplane wings.

Another object of my invention is the prevention of flaming of thevapors of fuel dumped from airplanes while in flight.

A further object is the provision of fire prevention and extinguishingmeans wherein the very input heat which is necessary to initiate andsustain the fire is the actuating or triggering means for renderingoperative the prevention and extinguishing means.

Still another object of the instant invention is the provision of fireprevention and extinguishing means which are practical and economicallyfeasible to utilize in connection with a wide variety of applications,but which, nevertheless, are highly efiicient in operation.

Other objects, features and advantages of the invention will becomeapparent as the description thereof pro-- ceeds when considered inconnection with the accompanying illustrative drawings.

In the drawings which illustrate the best mode presently contemplated byme for carrying out my inventron:

FIG.1 is a sectional view of a vertical, closed top, storage tankembodying my invention;

FIG. 2 is an elevational view of an open top, vertical storage tankembodying a slightly modified form of my invention, portions broken awayfor purposes ofillustraton;

FIG. 3 is a section taken on line 3-3 of FIG. 2;

FIG. 4 is a sectional view of a horizontal storage tank embodying theinstant invention;

FIG. 5 is a section taken on line 5-5 of FIG. 4;

FIG. 6 is a'fragmentary front elevation of an airplane wing and engineembodying my invention;

FIG. 7 is a section taken on line 77 of FIG. 6; and

FIG. 8 is a fragmentary bottom view of an airplane wing showingschematically an additional feature of the instant invention.

Heretofore it has generally been taught that three factors are involvedin the initiation and continuationof fire whenever a solid or liquid isthe source of the flammable gas or vapor. Basically, these factors areheat, fuel, and oxygen. It is well known that fire can be prevented bythe elimination of one of these factors, and that once started, fire canlikewise be extinguished by the elimination of one of these factors. Inaccordance with the instant invention, however, it is contended thatthere are actually six observable or measurable factors involved in thelife cycle of a fire and that elimination of any one of these sixfactors will serve to'effectively prevent initiation and/ orcontinuation of the fire. These six factors are:

(l Input-heat;

(2) Fuel (a vapor or gas);

(3) Oxygen (from air);

(4-) Proportioning;

(5) Mixing (for near-burning or remote-burning); and (6) Ignitioncontinuity With the above factors in mind, it has been found desirableto control the initiation, spread and termination of fire by providingmeans for intercepting the inputheat before it reaches the flammablevapor or gas source whereby to prevent vaporization of the latter,without which flame is incapable of initiation. Furthermore, it

is the basic concept of my invention to cause non-flammable vapor to mixwith any flammable vapor that may result from only partial interceptionof the input heat, said mixture taking place before said vapors come incontact with the surrounding atmosphere or before the occurrence ofignition and to provide, where desirable, intercepting means which initself is triggered by the input heat it absorbs to convert anon-flammable vaporizing liquid into its non-flammable vapors to tocause the release of non-flammable liquids, vapors or gases stored underpressure. As will be obvious, combustion will be prevented when theproportions of the resulting mixture contain a sufliciently highpercentage of non-flammable components. While I prefer to dilute theflammable vapors, it will be understood that flame can be just as wellprevented by diluting the oxygen supply with nonfiammable gas or vaporbefore mixture thereof with the flammable vapors.

Referring now to the drawings, and more particularly to FIG. 1 thereof,there is shown a conventional metallic storage tank it) having therein asupply of flammable liquid .12 such as gasoline, kerosene, or the like.Any desirable means, such as duct 14, may be provided for replenishingor removing the supply 12 from the tank 10. At the open upper end oftank 10 there is provided a combination cover and interceptor,constructed in accordance with the instant invention, and generallydesignated at 16.

The cover 16 is preferably constructed of any highly heat conductivemetallic material and comprises a substantially conical roof is having adownwardly depending peripheral skirt 20 in spaced relation to the wallof tank 1t Cover. 16 further comprises a bottom partition or wall 22which seats on the upper edge of tank 1d, it being understood that thelatter may be provided with a marginal flange 24 in order to provide asuificient base surface for receiving said cover 16. Preferably, a heatinsulating layer 26 is interposed between partition 22 and flange 24.

Centrally disposed in partition 22 and communicating with the interiorof tank lib is a passageway or channel 28 which extends upwardly towardroof 16 but terminates in spaced relation thereto whereby to define anopen area 30 which functions as a mixing chamber. As will be noted, thepassageway 28 is in alignment with an outlet 32 carried by roof l6 andcentrally disposed with respect thereto. Surrounding passageway 28 is alower reservoir 34 defined by partition 22 and roof 16, said reservoirhaving an inlet 36 extending through roof 16 in order to facilitatereplenishment thereof. Located above reservoir 34 is a second reservoiror compartment 38, said compartment being enclosed and having an inlet4%), ducts 42 communicating with passageway 28, and a conduit 44 leadingto a spray nozzle 46 located within said passageway. Preferably, a cover16 is painted black whereby to establish maximum radiant heat absorptioncharacteristics.

In operation and use, the reservoirs 3d and 38 are each filled with avaporizing, non-flammable liquid, and preferably, reservoir 34 is filledwith water, while cornpartmcnt 33 is filled with carbon tetrachloride orthe like. Actually, the specific liquids utilized are not critical solong as they are vaporizing and non-flammable, and accordingly, suchliquids as monobromomonochlorodifluoromethane, methyl bromide,dibromodifluoromethane, dibromotrafluoroethane, bromochloromethane, aswell as liquids of the Freon class, can be used, if desired. At anyrate, no matter What liquids be utilized, it will be understood that asradiant input heat is directed toward tank It it will be intercepted bycover 16 and its depending skirt 26. Since the cover 16 is highly heatabsorbent, as heretofore described, and since said cover makes contactwith tank 1% only through the medium of heat insulating l yer 26, itbecomes apparent that the transfer of the input heat to the tank It?proper is substantially minimized. In the meantime, the application ofheat to the cover 16 causes vaporization of the nonflammable liquidscontained in the reservoirs 34 and 38. As will be obvious, thenon-fiammable vapors from reservoir 34 will pass upwardly to mixingchamber 30 and thence outwardly through outlet 32, while the vapors fromcompartment 38 will pass through ducts 42 to passageway 23 and thenupwardly and outwardly through said outlet 32. Since the only outlet forwhatever vaporization that does take place of the flammable liquid intank It} is through passageway 28, it becomes obvious that saidflammable vapors are thoroughly mixed in the mixing chamber 36' with asutficient proportion of nonflammable vapors to render the eflluentmixture nonflammable before said mixture comes in contact with thesurrounding atmosphere and oxygen and a source of ignition. Thus it willbe seen that I have provided an entirely self-contained unit whichintercepts the radiant heat energy before it comes in contact with theflammable liquid and which further employs said heat for vaporizing anon-flammable liquid. The non-flammable vapors in turn are caused to mixwith whatever flammable vapors do occur, before said mixture comesincontact with the surrounding atmosphere.

When a liquid such as Freon is used in compartment 38, whereintemperature rise causes rapid pressurization of same, I prefer to takeadvantage of this fact by Wetting down, so to speak, the flammablevapors as they pass through passageway 28. Thus I have provided aconduit 44 for connecting compartment 38 with spray nozzle 46, thelatter being located Within the passageway 28, whereby as thetemperature rises and the Freon in substantially enclosed compartment 38becomes highly pressurized, non-flammable liquid spray will be forcedinto, said nozzle and will spray therefrom, mixing with the effluentflammable liquid, vapors or gases. At the same time, the non-flammablevapors from the Freon will pass through ducts 42 into passageway 28, asaforedescribed.

Referring now to FIGS. 2 and 3, a slightly different application andconstruction of the instant invention is illustrated. More specifically,thereis shown an opentop. storage. tank 4 8 having therein a supply offlammable liquid 56. A floating inhibitor generally designated at 52 ispositioned on the upper surface of the liquid 50 and comprises areservoir 54 having a continuous side wall 56 and a bottom wall 58. Aswill be seen most clearly in FIG. 2, the uppermost portion of side wall56 is provided with a plurality of spaced openings 60 definingtherebetween upwardly extending struts 62 on which is mounted a top wall64 of slightly smaller peripheral dimension than tank 48 whereby todefine an open area or mixing chamber 66 therebetween. The upper surfaceof top wall 64 is preferably black whereby to impart thereto maximumheat absorbing characteristics, and centrally secured thereto is aliiting ring 68. The under surface of Wall 64 is provided with aplurality of radial, downwardly depending heat conductive fins 70. Aplurality of flotation chambers 72 are secured to the lower surface ofbottom wall 58 whereby the inhibitor 52 may be crane lifted into placewithin the tank 48 and will be floatingly received therein.

In operation, this form of my invention is quite similar to thatdescribed in connection with FIG. 1. More specifically, any desirablevaporizing non-flammable liquid is placed Within the reservoir54,whereby upon application of input heat to the unit, non-flammable vaporswill flow outwardly through openings 60 and upwardly through mixingchamber 66. Since the flammable vapors from the liquid also must passthrough the space 66, said flammable vapors will be diluted by thenon-flammable vapors before coming in contact with the surround ingatmosphere and oxygen. The dilution of the flammable vapors is such thatthe mixture is no longer flammable even when it is further mixed withair in the presence of a source of ignition.

Here again, the construction is such that much of the input radiantenergy will be intercepted and absorbed by the inhibitor. Hence, the,exposed top of the latter is preferably black, and the heat conductivefins 76 will function to cause quick transfer of the heat to thevaporizing, non-flammable liquid whereby to insure rapid vaporization ofthe latter. As will be obvious, my inhibitor 52 is, in eifect, portableand may rapidly be" positioned within any open tank should a firedevelop. In addition to its fire extinguishing function, it will beunderstood that, if desired, the inhibitor 52 could also be permanentlypositioned within a tank in order to function as fire preventativemeans.

FIGS. 4 and 5 illustrate my invention as applied to horizontal storagetanks, and in this embodiment the 7 basic principle is to automaticallyenvelope the tank with a non-flammable vapor responsive to a suflicientapplication of input heat. Thus, the tank 76 is mounted on a pair ofspaced concrete pedestals 78 and is positioned between a pair ofsubstantially identical, longitudinally extending enclosures generallydesignated at 80. Each of the enclosures 80- is provided with alongitudinally extending partition 82 defining a pair of separate,open-top compartments 84 and 86. A plurality of ducts 88 extend from oneof the enclosures and terminate adjacent the upper portion of tank 76,While a plurality of somewhat longer ducts 96 extend from the oppositeenclosure and terminate adjacent the lower portion of said tank.

Briefly summarizing the operation of this form of my invention, thecompartments 84- and 86 are filled with any vaporizing, non-flammableliquids, although I prefer to use water in the outer compartments 84. Aswill be obvious, the enclosures 80 will serve to intercept input heatdirected toward the tank 76, and at the same time the application ofheat to the enclosures will vaporize the liquids in the compartments 84and 86, causing nonflamrnable vapor to flow through ducts 88 and 9t andsubstantially envelope the tank 76 whereupon. any flammable vaporthatmay emanate from the latter will be rendered non-flammable beforecoming into contact with the surrounding air. In this respect, it willbe noted that the enclosures 30 are designed to provide a relativelyrestricted passage 92 above the, tank 7 6 whereby to better insureproper mixing of the non-flammable and flammable vapors or gases beforethey come in contact with the oxygen of the surrounding air.

While each of the aforedescribed illustrations of my invention Works onthe principle of diluting the hydrocarbon before it comes in contactwith the air, whereby the mixture will be non-flammable, it will beunderstood that the opposite approach can be utilized, if desired, withsubstantially the same results. More specifically, if the air or oxygenis sufficiently diluted before mixing with the hydrocarbon, flaming willbe prevented. This specific approach is particularly adaptable inconnection with aircraft fire prevention and extinguishment and may bereadily applied to fuel-tank sections of airplane wings, enginesections, jet power pod sections, etc. Since the necessary radiant-heatabsorbing areas can be built of very thin, light metal, the inclusion ofmy invention will add very little weight to an airplane wing structure,and, if desired, the web structures of the wingscan be used tosimultaneously serve the double function of providing strength for thewings and at the same time acting as containers for the non-flammablevaporizing liquid. Reservoirs, with connecting piping of small tubing,can be located in the main fuselage of the plane for replenishment ofthe non-flammable vaporizing liquid'either by gravity or pressure feed.

Referring now to FIGS. 6 through 8, an illustrative embodiment of thisform of my invention, as applied to aircraft usage, is shown. Anairplane wing 94 having an engine 96 has provided within its webstructure a lightweight metal container or reservoir 98. Preferably, apair of these containers or reservoirs are provided for each engine, andare located adjacent to and on opposite sides thereof. Conduit or tube100 extends from each reservoir 98 and is directed toward the spacesurroundin the engine-whereby when the reservoirs are filled with avaporizing, non-flammable liquid, radiant heat from hostile fire aroundthe engine 96 will cause vaporization of said liquid, and thenon-flammable vapors will flow through conduit 1% and mix with theoxygen in the atmosphere surrounding the engine. This dilution of theoxygen renders the surrounding atmosphere non-nammable whereby hostilefire is prevented from spreading within the power pod or wing structure.

In order to further inert the atmosphere within the wing structure, asecond conduit 102 discharges nonflammable vapors from reservoir 98 tothe interior of the wing space. This is important since the engine fueltanks are usually located Within the wing structure and are normallysubject to input heat from a hostile engine fire capable of vaporizingthe contents of said fuel tank and thereby creating a serious firehazard. By inerting the area surrounding these fuel tanks, near exposureto the radiant heat from flame is prevented.

In connection with this form of my invention just described, anadditional tube or conduit 104 may be provided to carry vaporizing,non-flammable liquid from the container or reservoir 98 to a pointadjacent the outlet 106, through which fuel is dumped while the aircraftis in flight. More specifically, for any one of a number of reasons, itmay become necessary or desirable to jettison the fuel supply of anaircraft in flight, and it will be understood that the high-speed airstream into which the fuel is dumped will cause atomization of theliquid, resulting in the formation of flammable vapors. Should theaircraft engine exhaust ever inadvertently come into contact with theseflammable vapors, an explosion could conceivably occur with disastrousresults. Accordingly, I prefer to render the jettisoned fuelnon-flammable by causing it to mix with a proportion of vaporizing,nonflammable liquid prior to being introduced into the air stream. Thiscan be most simply accomplished by causing vaporizing non-flammableliquid to flow from reservoir 98 through conduit 104 by gravity orpressure means (not shown) to a point adjacent and preferably ahead offuel outlet 106. The fuel opening and the opening from the proportioningconduit or tube may be closed by a remote control common cover (notshown) which closes and opens both of them simultaneously, or theclosure of the tube may be opened thermostatically by the interceptionand absorption of radiant heat energy or by other means. When both portsare open, the effect will be to cause the non-flammable vaporizingliquid flowing from reservoir 98 to mingle with and flow confluentlywith the fuel from the aircrafts fuel tanks, resulting in both beingatomized simultaneously in the high-speed air stream passing theoutlets. The eflect of such simultaneous atomization and vaporization ofnon-flammable vaporizing liquid and flammable vaporizing liquid will bethe formation of a mixture of non-flammable and flammable components inproportions which are non-flammable in total when further mixed with thesurrounding air, even in the presence of a source of ignition.

While there is shown 'and described herein certain specific. structureembodying the invention, it will be manifest to those skilled in the artthat various modifications and rearrangements of the parts may be madewithout departing from the spirit and scope of the underlying inventiveconcept and that the same is not limited to the particular forms hereinshown and described except insofar as indicated by the scope of theappended claims.

I claim:

1. Apparatus for preventing and extinguishing combustion in open-topstorage tanks for flammable liquids, said apparatus comprising afioatable compartment of slightly less peripheral dimension than thetank interior, said compartment being substantially enclosed with theexception of a plurality of outlet openings located adjacent the upperportion thereof, said compartment being adapted to receive therein asupply of vaporizing non-flammable liquid whereupon application ofradiant heat to said tank will simultaneously cause vaporization of theflammable liquid therein and the non-flammable liquid in saidcompartment, said vapors mixing to produce a non-flammable mixturebefore contacting the surrounding air.

2. In the apparatus of claim 1, said compartment having an upstandingside wall and a top wall, said outlet openings being positioned at theupper end of said side wall and said top wall having a plurality of heatconductive fins extending into the compartment interior.

3. A non-combustible storage tank for flammable liquids and the likehaving a cover portion, an enclosed reservoir within said cover portion,a mixing area associated with said cover portion through which vaporsand the like emanating from said tank must pass before reaching thesurrounding atmosphere, and a passageway interconnecting said reservoirand said mixing area whereby vapors and the like emanating from saidreservoir must also pass through said mixing area before reaching thesurrounding atmosphere, said cover portion being insulated from saidtank and having a skirt depending in spaced relation thereto.

4. Apparatus for preventing and extinguishing combustion in a storagecontainer containing flammable material, said apparatus comprising acompartment located adjacent to said storage container, a supply ofvaporizing, non-flammable material in said compartment, means associatedwith said compartment for intercepting a sufficient proportion of inputheat directed toward said storage container from points outside saidcontainer to cause said non-flammable material to vaporize at least assoon as any vaporization of said flammable material takes place, andmeans causing said non-flammable vapors to mix with all said flammablevapors prior to mixing with the surrounding air whereby to cause amixture which is nonignitable by the temperature attained by the saidinput heat, said last mentioned means comprising a restricted mixingspace through which said flammable and nonflammable vapors must passbefore reaching the surround ing atmosphere.

5. A non-combustible storage container for flammable material and thelike, a cover portion for said container defining a restricted mixingspace through which flammable vapors from said container are free topass to mingle with the surrounding air, said cover portion otheraneWise blocking said flammable vapors whereby it is essential that theypass through said mixing space before reaching the surrounding air, anenclosed reservoir associated with said container, and meansinterconnecting said reservoir with said mixing space whereby vapors andthe like emanating from said reservoir will be forced into said rnixingspace, said reservoir being associated with said cover portion so thatheat absorbed by the latter will be directed to the former to causevaporization and pressurization of its contents at least as quickly asvaporization of the stored flammable material takes place. i' i 6 Amethod for preventing and extinguishing fiaining combustion fed by fuelvapors or gases frorn flammable material Within an enclosure andresulting from the application of input heat from an ignition sourcelocated erg: ternally of the enclosure, said method comprising the stepsof intercepting and absorbing controlled proportions of the input heatfrom said ignition source, utiliiing said intercepted and absorbed heatto cause the emission of non-flammable vapors or gases fromnon-flammable material held adjacent said enclosure, and mixing saidnon-flammable vapors or gases with all of the flarnrn-able vaporsflowing out from the enclosure. or with all the air flowing into theenclosure, prior to, the mixing of said flammable vapors and air witheach other, withihe proportion of non-flammable gases or vapors beingsuch that the resultant: mixture of non-flammable and 'flanmrnable gasesor vapors and air is non-ignitabie by the temperature attained from thesaid input heat, thus preventing ignition of the mixture whereby toinhibit spread of the fi e 9 th fl mmable ma i f 'al W thin s ad smefienc Cr n h fil th s a e t UNi-Tan STATES PATEN S 234,29I King Nov. 9,1880 2 3 9,431 Birge Mar. 29, 1881 1,386,232 Bole Aug. 2, 1921 1,394,060Bates o r. 18, 1921 1,775,846 Blaw Sept. 16, 1938 2,248,308 Rice July 8,1941 2,558,694 S peig June 2 6, 1951 2,706,005 Zingler Apr-Q 12, 19552,757,744 Malone Aug. 7, 1956

